The standard fire fighting nozzle is coupled to the end of a hose, held by a fireman and directs a stream of water substantially, directly forward at the fire. A number of variations have been disclosed which address the problems of producing various spray patterns and are often referred to as fog nozzles. Fog nozzles for many years have been an important aid in fighting fires by controlling, to some extent, radiant heat, reducing the temperature of a blaze, limiting the amount of oxygen within an enclosed area, and displacing large quantities of combustible gases from a confined area.
Fog nozzles which produce a dispersed spray pattern have a wide variety of structures, but the peripheral jet fire nozzle is most commonly used, because it has the ability to discharge a large amount of water in a straight stream in one position of adjustment and a lessor amount of water in a fog spray in another position of adjustment, all of which are directed in the forward direction.
The inherent problem that exists with all of the known prior art is that the fireman must make a choice between and compromise between the often times more effective straight stream mode which places a large amount of unrestricted water on the fire but which leaves the radiant heat and large quantities of combustible gases un-contained to pose a real danger to the fireman, or the fog mode which more effectively protects the fireman from radiant heat and gases but reduces the amount of water reaching the heart of the blaze.
In the peripheral jet nozzle one common means for producing the rearward fog spray comprises providing a row of equally spaced fixed teeth having a flat face in a circular ring at the discharge end of the nozzle in the path of a conical jet of water issuing forwardly from the interior of the nozzle. However, when the water strikes the face of each tooth, it deflects along the same line as the face of the tooth and the spray pattern consists of a conical row of small spaced jets, creating a gap in the outer conical spray pattern for each tooth. Likewise, there is a gap in the inner spray pattern between each jet of water. The characteristic “fingers” in the spray pattern are objectionable, because they permit radiant heat and gases to pass through the spray pattern. U.S. Pat. No. 4,653,693 addresses the problem of the “fingers” by forming an inner and outer spray pattern to form a single fully filled dispersed forward fog cone having a wide angle of divergence and a circumference free of gaps however, in this mode, the cone of water may provide a better protection for the fire fighter but no forward straight stream mode is provided. Also it can be noted that all the former art makes no effort to reduce in any way the reactive rearward force generated by the forward spray or stream. With larger nozzles this force often requires more than one man to control the hose and nozzle.
It is desirous, then, to provide a dual system which can not only produce forward straight stream but can at the same time produce a backward fog cone to arrest the radiant heat and gases and protect the fireman and persons or property being rescued while at the same time reducing the reactive rearward force generated by the forward stream or fog spray. Furthermore, it can be noted that in a dangerous rescue mode the forward fog can be deployed as well as the rearward cone offering further protection to the fireman and persons or property being rescued.